1. Technical Field
The present disclosure relates to a receiving device that controls a gain in response to power of a received signal.
2. Description of the Related Art
For wireless local area networks (LANs), the standardization of, for example, the Institute of Electrical and Electronics Engineering, Inc. (IEEE) 802.11ad communication specifications has been promoted. In IEEE 802.11ad, an access control method referred to as carrier sense multiple access/collision avoidance (CSMA/CA) has been adopted.
In CSMA/CA, a receiving device detects a signal existing in a wireless transmission path, and adjusts a gain for amplifying the detected signal such that a fluctuation range of the detected signal falls within a dynamic range of an analog-digital converter (ADC). In IEEE 802.11ad, a training sequence referred to as a preamble is given to the head of a packet, and the receiving device performs automatic gain control (AGC) using the preamble.
As a technique by which AGC converges at a high speed in a limited preamble section, a technique in, for example, Japanese Unexamined Patent Application Publication No. 2005-278017 is known. A wireless communication device described in Japanese Unexamined Patent Application Publication No. 2005-278017 stores an optimum gain value for AGC in past communication, and sets the stored gain value as a standby gain value for each AGC circuit during a standby period, thereby reducing the convergence time before an optimum gain value is decided when communication is resumed.